Gas turbine power plant having fuel cut-off valve actuated by an overspeed governor



2,609,656 -OFF VALVE OVERSPEED GOVERNOR p 9, 1952 D. M. PCOLE GAS TURBINE POWER PLANT HAVING FUEL CUT ACTUATED BY AN Original Filed April 15, 1944 3 Sheets-Sheet l WWW Sept. 9, 1952 M. POOLE 2,609,656

GAS TURBINE POWER PLANT HAVING FUEL CUT-OFF VALVE ACTUATED BY AN OVERSPEED GOVERNOR Original Filed April 15, 1944 3 Shets-Sheet 2 [71 22am 2?)?" in? Mlooip Sept; 9, 1952 D. M. POOLE 2,609,656

' GAS TURBINE POWER PLANT HAVING FUEL CUT-OFF VALVE ACTUATED BY AN OVERSPEED GOVERNOR Original Filed April 15, 1944 3 Sheets-Sheet 3 OSC/LLATOR gaze Patented Sept. 9, 1952 CUT-OFF VALVE ACTUATED SPEED GOVERNOR BY AN OVER- David M. Poole, Oak Ridge, Tenn.,assignor to United Aircraft Corporation, East Hartford, Conn, a corporation of Delaware Original application April 15, 1944,- Serial No. 531,310. Divided and thisapplication June 1'7,

1948, Serial No. 33,486

This invention relates to a control system for 1 an aircraft power plant which includes gas generators for supplying gas under pressure to a turbine which drives a propeller.- A burner may be used between the generators and the turbine for adding heat to the gas. This is a division .of Serial No. 531,310, filed April 15, 1944.

A feature of the invention is an arrangement for cutting off the fuel supply to the burner in the event of turbine overspeeding. Another feature is the complete cutting ofi of all fuel to the power plant when the turbine exceeds a pre determined speed.

Other objects and advantages will be apparent from the specification and claim, and from the accompanying drawings which illustrate an embodiment-of the invention.

Fig. l is a diagrammatic view ofthe power plant showing the fuel supply system.

Fig. 2 is a sectional view on a larger scale of one of the generators.

Fig. 3 is a diagram of the fuel control system and the electrical system.

Fig. v4 is a sectional view through one of the fuel injection devices.

Fig. 5 is an end view of an overspeed governor. The generators H] supply hot gas under pressure through a duct l2 to the intake of the turbine M. The latter is connected to a propeller system Idthrough gear reduction units 18 and 2t and shafts 2 2 and 2%. The turbine exhaust discharges as a jet through a restricted nozzle 26 which may be directed rearwardly of the air- .craft to. produce an additional propulsive thrust.

The gas is heated between the generators and the turbine ,by discharging fuel into duct [2 through a fuel nozzle 30 supplied by a fuel line 32. Fuel is admitted at a point spaced far enough from the turbine to assure complete burning of the fuel before the power gas has reached the turbine inlet. i

; As shown in Fig. 2, each generator,-which supplies hot compressed gas, maybe in the form of afree-piston engine-and-compressor unit comprising an engine cylinder having reciprocating pistons 36 and 33 to which compressor pistons 69 and 42 in cylinders 44 and 45 are 1 Claim. (01. sop-:13)

.are maintained at equal distances from the center of r the engine cylinder by a linkage of which rods :55 may form a part.

lntake manifold 56 conducts air tosets of intake valves 58 through which air alternately enters opposite ends of thecompressor cylinders.

The compressed air leaves the cylinders through sets of discharge valves 60 also at opposite ends of the compressor cylinders and passes through scavenge manifold 62 and through ports 64 which are uncovered by pistons 36 and 38 at the end-of the power stroke. Air entering these ports is blown through the engine cylinder and discharges through exhaust ports 66 into exhaust manifolds 58, Fig. 2. y 1

The intake manifolds of the several units are connected to an intake duct iii. Thescavenge manifolds are interconnected by a pipe 12. The exhaust gases flow from the exhaustmanifolds through pipes 14 into duct I2.

Referring to Fig. 3, fuel for the generators and 1 the, burner is delivered from a supply, not shown,

through a pipe 16 to a pump 18.

From this pump, fuel flows through a conduit to, a control device 82 by which the total fuel flow to the power plant is controlled. From control device 82 fuel flows through a conduit 84 to the generators HE. A part of the fuel from device 82 may discharge through a conduit 66 to a control device 83 by which the burner fuel is controlled. From device 88 a conduit 99 directs fuel to line 32, Fig. 1, and thence to the burner nozzle.

Pressure in the supply conduit 89 is adjusted by relief valve 92 in a bypass for a pump. Fuel I82 alternately connects port I94 with a supply port B6! or a vent port; I88. .nected bya conduit Hi! to a supply of control vfluid: which may be the conduit 80 in which Port Ill! is conevent a part of the fuel isused as the control fluid Vent port I {38 may be connected by a duct III to conduit 16.

The end of plunger 96 has a solenoid ll2'in spaced relation to a stationary coil I M in the end of the casing I 15 for the control device 82. These coils H2 and H4 have bucking fields and the plunger which adjusts the supply of control fluid to device BB is moved by a change in the repulsive eifect between these coils. Coils H2 and [M are connected in series andiinopposiwhich may be located in a part of the device I06. These valves are mounted on a stem 22'! having a head 228 engaging a spring 239 by which the valves are urged into closed position. A magnetic coil 232 normally holds the valves in the open position shown.

An overspeed governor which may be of conventional construction is mounted on the turbine shaft and normally closes a circuit 234 includin 235 by a spring 231. When the centrifugal force acting on the ring, which is eccentric to the shaft axis, overcomes the load on the spring and moves the ring into the dot-dash position shown, the ring engages the plunger 239 to open the circuit 234 including the contacts 24l on the base 243, and the connector 245 on the plunger.

Coil 232 is mounted on a plunger 235 normally held in the position shown against a flange 238 by a spring 240. Plunger 236 is in a position to engage piston 216 when the latter approaches the left-hand end of its movement, so that upon a failure of control fluid in cylinder 2|! or upon shut-down of the power plant, piston 2 I 6 will engage the plunger, and, by the action of spring 2 l8 which is heavier then spring 249, will close valves 225 and 226.

To maintain the desired rack setting during starting thereby avoiding the injection of excessive quantities of fuel, a plunger 216, Fig. 1, on rod I28 slides in a casing 218 and is adapted when lever I40 is in starting position to connect a port 280 to a vent port 281. Port 280 is connected by a duct 282 to a port 284 in cylinder 2|! spaced from the inlet port 220 the distance that the piston 2 l6 should move for placin the racks of the injection devices in starting position. Port 28I may be connected by a conduit 286 to the supply conduit 16.

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described, but may be used in other ways Without departure from its spirit as defined by the following claim.

vice for the unit, a fuel nozzle in the combustion chamber, a fluid connection from said supply means to said injection device and to said nozzle, means for adjusting the quantity of fuel delivered to said device from said supply, other means for adjusting the quantity of fuel delivered to said nozzle from said supply, a valve in said fluid connection independent of both of said adjusting means, electrical means associated with said valve for holding said valve in open position, a circuit including said electrical means, and an overspeed governor driven by the turbine and arranged upon overspeeding of the turbine to control the circuit to cause the valve to close.

DAVID M. POOLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,931,096 Warner Oct. 17, 1933 1,934,631 Taylor Nov. 7, 1933 2,0 5,991 Lysholm Oct. 19, 1937 2,147,935 Steiner Feb. 21, 1939 2,292,288 Pateras Pescara Aug. 4, 1942 2,306,953 Jung Dec. 29, 1942 2,336,052 Anderson et a1. Dec. 7, 1943 2,355,177 Pateras Pescara Aug. 8, 1944 2,376,143 Edwards May 15, 1945 2,411,065 Silvester Nov. 12, 1946 2,4 3,472 Welsh July 8, 1947 2,439,473 Kalitinsky Apr. 13, 1948 2,444,254 Hewitt June 29, 1948 2,447,124 Kalitinsky et al. Aug. 17, 1948 2,468,157 Barlow Apr. 26, 1949 FOREIGN PATENTS Number Country Date Great Britain Apr. 9, 1931v 

